Plaster board



- 1,646,598 O t 25, 1927- L. 'ROUTT PLASTER BOARD Filed April 17, 1925 IgEN TOR.

' TTORNEY Patente Get. 25, 19?.

? ORVILLE L. ROUTT,

OF LOS ANGELES, CALIFOBINIA, ASSIGNOR TO PLASTOID PRODUCTS,

INC., A CORPORATION OF CALIFORNIA.

rras'raa BOARD.

Application filed April 17, 1925. Serial No. 23,855.

My invention relates to plaster board or plaster lath and more particularly to water proof plaster board and plaster lath of the character used as a wall foundation and onto which plaster is applied. I

In waterproof plaster board now used,

the paper is treated. with water proofing substance on its outer face and its untreated face is placed next to the plastic substance of which the board body is'made. This insures a good bond between the facing sheet and the body of the board, but leaves a smooth, treated surface outermost to receive the plaster. This surface is so smooth and because of the water proof nature of it, it is diflicult to make the plaster adhere readily thereto, and this is especially true on ceiling work. The plaster falls off almost as fast as it is applied. To place the waterproof surface of the paper next to the plastic matter of which the board is made is objectionable for the reason that a bond cannot be secured between the paper and the body of the board and the paper readily comes loose from the board body.

4 I have conceived a new idea for manufacturing plaster board and plaster lath and by means of which I can place the untreated surface of the cover sheet outside and the water proofed surface of the paper next to the plastic matter or body of the board. I

accomplish this by manufacturing such a board having channels or key-ways formed therein and by interlocking the paper cover 85 sheet in said channels, or key-ways, with its treated side next to the body and its untreated surface outermost. The paper is held in place in.,the channels, which have the' overhanging sides, with the untreated side 40 thereof outermost. The plaster is easily ap-' plied thereto, and adheres as fast as it can be applied because of the affinity of the paper for the moisture in the plaster, which can, of course, penetrate only to the water proof substance on the opposite side of the paper. The application of the plaster to the board also further interlocks the paper to the key-ways or channels because the plasticmatter is forced 'into the channels and crowds thepaper even more closely into the angles or corners of the channels. This makes a-good job and greatly facilitates the application of the plaster to the plaster board or plaster lath thus manufactured,

'companying sheet of'drawings, which I will and at the same time gives a water proof product. i

In order to more fully explain my invention, I have illustrated the same on the acnow describe. v

The figure shows apiece of plaster board, or plaster lath, embodying my invention, with the face sheet rolled back to indicate the water proof substance on its face next to the body of the board.

In the drawings, 1, designates the body of the plaster board, or plaster lath, made of any suitable plastic material which hardens after being formed with a face sheet 2, on one side and on the other side having formed therein the channels or key-ways, 3, 3, having the overhanging sides, at 4, 4, with a cover sheet, 5, fitted thereinto and having its inner surface treated with any suitable water proof substance, designated 6. The outer face of said paper is untreated and has absorbent property and when plaster, designated- 7, is applied thereto, it adheres thereto very readily and as it is forced into the channels or key-ways, 3, 3, it crowds the paper back into the corners of the said channels and thus both paper and plaster is interlocked to the plaster board, substantially in the manner indicated.

I do not limit the invention to the details shown'for illustrative purposes, except as-I may be limited by the hereto appended claims.

I claim:

1. Plaster board and the like formed of plastic material and having a cover sheet with its side next to said plastic material water proofed and its outer side untreated, and means interlocking said sheet to said plastic material, and means whereby when plaster is applied to said cover sheet it is in terlocked to said sheet and said plaster board. 7 i

2. Plaster board and the like formed of plastic material and; having a cover sheet with its inner face water pro'ofed and its outer face untreated, said plaster board having channels or key-ways formed therein,

and said cover sheet being interlocked in said channels orkey-ways and forming plaster-receiving and holding means Y oir said plaster board. 7 I p r 3'. In plaster board a body of plastic material having key-ways formed therein and to adhere thereto and to be interlocked in a sheet of paper treated with water proofing said key-Ways. substance on its side next to said body and Signed :at Los Angeles, Los Angeles 10 pressed into said key-Wa s and interlocked County, California, this 9th day of April,

5 thereto, the outer face 0 said paper being 1925.

capable of absorbing moisture, whereby plaster applied to said outer face is caused ORVILLE L. ROUTT. 

